Indiana University, Bloomington
Indiana-Princeton-Tennessee Astrobiology Initiative (IPTAI): Detection of Biosustainable Energy and Nutrient Cycling in the Deep Subsurface of Earth and Mars
Our decision to seek membership in NASA’s Astrobiology Institute is motivated by the desire to bring our expertise in deep subsurface ecosystems to bear on the scientific and technological difficulties that will be encountered during the exploration of life beneath the surface of Mars. Our center will be a consortium composed of 9 senior level investigators, three of which are from DOE laboratories (PNNL, LBNL and ORNL) and five from academic institutions (Univ. of Tennessee-UTenn, Indiana University-IU, Univ. of Toronto-UT and Princeton University-PU) and one from Lunar Planetary Institute. We hope to complement the already excellent research being performed by NAI on the Mars focus area and believe our center’s expertise in subsurface ecosystems, and access to unique facilities and field sites will enable us to develop synergistic relationships with other biological, geological and planetary research in NAI.
Our NAI would focus upon subsurface microbial communities that have been sequestered from the surface photosphere for tens to hundreds of millions of years and the environments that support their in situ activities. These terran ecosystems would represent the closest analogy to what might exist beneath the cryosphere of Mars. We seek to characterize the microbial, mineralogical and geochemical interactions, the isotopic signatures of the organic and inorganic gaseous, aqueous and metallic species, the interspecies and interkingdom communications and interactions, the genomic diversity and capabilities, the proteins expressed and their origin and the metabolites created and exchanged. This information will be used to design life detection approaches that will be tested in well-characterized field locations as a first step towards the design of flight-capable life detection instruments for future Mars drilling missions.
The proposed research will address five of the seven goals outlined in the Astrobiology Roadmap. The study of deep subsurface, ecosystems in ancient groundwater is directly relevant to the exploration for extant life in the subsurface of Mars, Objective 2.1 of Goal 2-Life in Our Solar System. In geological terranes where thermal overprinting has eradicated microbial life and which have remained isolated from the surface since that thermal episode, our investigations will determine the type of prebiotic compounds that can be formed in the subsurface and whether life itself could have been spawned beneath the planet’s surface. Hence our proposed research touches upon aspects of Goal 3-Origins of Life. Because we have accessed our deep subsurface ecosystems by way of the deep Au mines of South Africa, characterization of the geochemical, lipid and isotopic signatures preserved in these rocks will enable us to answer some of the questions raised in Goal 4-Earth’s Early Biosphere and its Environment. We will explore the evolution, environment and limit of life, Goal 5, by examining the community composition of subsurface ecosystems in different geochemical venues and by performing in situ experiments to see how the community evolves in response to environmental changes. Our research is particularly relevant to Objective 5.3, the determination of survival strategies that permit organisms to maintain viability in a radioactive environment for millennia. Finally, our research is already identifying isotopic signatures that indicate the presence of subsurface life, Objective 7.1 of Goal 7-Signature of Life, and our research plans will determine whether these signatures are preserved in the rocks.
Education and Public Outreach (EPO) activities in IPTAI are designed around three areas of emphasis. First: educational workshops for undergraduates and high school teachers where participants actively collect and interpret data from laboratory and field experiments. Second: public outreach through a web site with premiere-quality digital media including animations and video that illustrate how and why scientists conduct research in deep mines. Third: mentoring undergraduate and graduate research at Indiana, Princeton, and Tennessee universities. These astrobiology students will work with faculty to design a series of web-based quantitative and investigative activities for all pre-college students but highlighting the diverse careers of leading women on the IPTAI team.
Inclusion of collaborators from the School of Fine Arts, IU Instructional Support Services, and University Information Technology Services at Indiana University is an unusual aspect of this proposal. High-resolution digital video/audio materials will be collected during field experiments and will be use in both research and educational components of the IPTAI. Videos produced by scientists will document research methods in a substantially different way from conventional commercial films. We hope to capture examples of both set-backs and advances in research resulting from unanticipated and challenging conditions in deep mines. Given severe time and access constraints in deep mines, digital documentation of the physical conditions and the configuration of instruments are essential for interpretation of experimental results.